An algorithm is a set of instructions or rules that a computer follows to perform a specific task or solve a problem. It's like a recipe that tells the computer what steps to take to complete a task.

For example, a sorting algorithm is a set of instructions that tells the computer how to arrange a list of items in a particular order, such as from smallest to largest. Another example is a search algorithm, which tells the computer how to look for a particular piece of information in a large database or document.

Algorithms can be very simple or very complex, depending on the task they are designed to perform. They are an essential part of computer programming and are used to automate tasks, analyse data, and make decisions based on predefined rules or criteria.